1. Field of the Invention
The present invention relates to a method and device for forming a detail by means of superplastic forming, wherein a foil or plate is heated to a suitable temperature and simultaneously exposed to a fluid pressure so that the foil or plate is slowly deformed to a predetermined shape.
2. Description of Related Art
It is previously known to use superplastic forming in order to shape details. The conventional method is described, for instance, in U.S. Pat. No. 4,181,000 the entire disclosure of which is expressly incorporated herein by reference. This patent discloses fixing a thin plate in a mold in which one mold part represents the shape of the finished detail. The plate is heated to a temperature which is considerably below the melting point of the material (usually 50-80% of the melting point measured in degrees Kelvin) while two opposite surfaces of the plate are simultaneously exposed to a comparatively limited pressure difference so that the material slowly, (i.e., over a period of 10 minutes to 2 hours), flows out and is pressed towards the mold part and achieves a corresponding shape. This prior art method has the advantage that when producing the detail only one mold part corresponding to the desired detail shape is needed. However, the prior art method suffers from the disadvantage that it is rather slow since the entire mold part and thin plate must be heated. It also requires a mold part, and replacement of the mold part with another mold part should a different shape be desired.